1. Field of the Invention
The present invention relates to the field of drivers for photoflash diodes, and more particularly to the field of drivers for photoflash diodes using current sink with low and fixed drop-out voltage. Specifically, the present invention relates to the circuits and control methods that are used for driving photoflash diodes in portable battery devices.
2. Description of the Related Art
Portable battery devices drive photoflash diodes using a controller to coordinate the use of the battery power. Existing solutions drive the photodiodes from a fixed voltage and then control the diode current through a controlled current sink or current source. However, at low diode current most of the power is wasted through the current sink.
Accordingly, there exists a need for a charging system or circuit which is able to overcome the above mentioned drawbacks.